Cases for holding compact discs are well known to the art. Such cases are commonly made of molded styrene and are a relatively inexpensive packaging which is required to house and display the discs for sale. Even though the case is relatively inexpensive, when compared to the cost of the CDs it holds, it must be strong enough to hold the discs over a long period of time and withstand frequent opening, closing and dropping. Industry requirements have dictated the dimensions of the case. Sizes greater than these standards, and especially greater thickness, have led to a lack of acceptance by the consumer because an oversize case is more difficult to store, especially by those who own large numbers of CDs.
The recording industry currently markets works which are so long they require more than one disc. Digitized information for research purposes frequently requires more than one disc also. Increasing the thickness of the case to accommodate a second disc is not always acceptable to the consumer. The industry has sought a case for two CDs which has the same thickness as a case for the single CD.
Popular cases currently available for storing CDs include a rectangular base, a corresponding rectangular cover pivotally connected to the base and a rectangular tray for holding the CD fixedly connected to the base. The rectangular tray includes a circular recess for receiving the disc and a central circularly-shaped, radially-ribbed clamp which receives the center hole of the CD by means of an interference fit to hold the CD in the case.
The U.S. Pat. No. to Lammerant et al., 5,244,085 and the U.S. Pat. No. to Dunker, 5,284,248, disclose a modification of existing CD cases which enable the storage of two CDs in a case which previously had been adapted to hold only one CD. To provide for holding two CDs, a tray which heretofore had been fixedly held within the base of the case is pivotally mounted in the base so that access to the tray can be gained from either side of it. The CDs are held by a tenon system. The tenon system includes pawl teeth which stand around a central hole disposed in the tray. Half of the pawl teeth stand substantially perpendicular to the face facing the cover and the other half stand on the face facing the base. One of the sets of teeth holds one CD with a pawl action and the other set holds another CD on the opposite side of the tray with the pawl action. The individual teeth are held on a ring disposed within the central hole in the tray. The ring is suspended from the central hole by a radial arrangement of spokes. I have found the spokes are relatively weak and cannot always support the weight of the CDs they are called on to hold. Dropping a case will frequently break the spokes and render the tray inoperative.
To provide additional strength to the tray and the spokes (and to allow the teeth to move laterally without breaking) the composition of the tray is modified by doping it with a rubber to make it more resilient. Pure styrene is quite brittle and can be used for the base and the cover. Doping the styrene of the tray causes it to become opaque and adopt the color of the dopant. Literature is conventionally disposed within the case against the cover, the base and the spline. This literature provides sales and identification material. Information stored beneath the tray cannot be seen through the tray. Since CDs are now manufactured with promotional material on both sides, it is beneficial to use a transparent tray. But since the styrene is extremely rigid and the teeth which hold the CDs break easily it has not been possible, heretofore, to provide an acceptable, unitarily molded tray without opacity producing additives.